Field of the Invention
The present invention relates to an operating device for a flush water tank assembly, a flush water tank assembly, and a flush toilet, and more particularly to an operating device for a flush water tank assembly, which starts the supply of flush water to a toilet by opening a discharge valve on a reservoir tank supplying flush water to a toilet, a flush water tank assembly, and a flush toilet.
Description of Related Art
For some time, known operating devices for a flush water tank assembly, for operating a discharge valve of the flush water tank assembly to supply flush water to a toilet have included those in which, as in Patent Document 1 (Japanese Patent Unexamined Publication No. 2014-190131), for example, for a discharge valve apparatus for opening and closing a discharge valve on a flush water tank by up and down movement (a “direct-type discharge valve apparatus”), the amount of movement of the discharge valve main body in the up-down direction is controlled by controlling the amount of movement of an operating wire, such as the amount of lifting of an operating wire linked to the discharge valve main body (or the winding amount by which an operating wire is wound up).
Conventional operating devices for a flush water tank assembly such as that set forth in Patent Document 1 include an operating member such as an operating handle or the like which can be rotated by a user, and a pulley for winding up an operating wire in tandem with the rotation of this operating member. The operating member and pulley are in a mutually constantly linked state regardless of functional state, and the flush water amount supplied from the flush water tank assembly to the toilet is determined in response to the elapsed time from the start of the opening of the discharge valve by the rotation of the operating member and pulley at initial position winding up the operating wire, up to the closing of the valve when the discharge valve body drops together with the water level inside the flush water tank, i.e., the operating time (operating member operating time) from start to completion of operation of the operating member. Hence, for example, the longer the time over which the operating handle and pulley rotation state is maintained, the operating wire wound-up state is maintained, and the discharge valve lifted state is maintained, the longer is the operating member operating time or the discharge valve main body valve opening time, thereby increasing the amount of flush water supplied from the flush water tank to the toilet.
On the other hand, while the amount of flush water usable for toilet flushing has been decreased to a regulation amount of approximately 3.8 L, for example, in conjunction with the conservation of flush toilet water in recent years, valve opening time can, depending on the length of the operating member operating time, become longer than the discharge valve opening time during which flushing can be effected using a flush water amount within regulation amount, causing the problem that toilet flushing using a flush water amount controlled to be within a regulation amount is difficult. Another problem is that in the above-described conventional operating device for the flush water tank assembly in which the operating member and pulley are mutually constantly linked irrespective of functional state, there is a limit on the extent to which the operating member operating time can be shortened, and operability and ease of use are compromised.